Pursuit-evasion games for a team of UAVs under dynamic environment

Abstract

Based on the interaction protocols of Contract Net and Subscribe-publish, a distributive pursuit-evasion algorithm is proposed for a team of pursuit UAVs to pursue an evasive UAV in a dynamic environment with threats. The pursuit UAVs fly to the suspicious area according to D* algorithm. If any threat is detected within the neighborhood of a UAV, it updates the map. If the evader is detected, the pursuit UAV (initiator) sends call-for-proposals messages to other pursuers. The other pursuers use D* algorithm to estimate their steps to reach the evader and submit their proposals. The initiator picks up the proposals for evaluation, chooses the nearest ones to join the pursuit team, sends accept-proposals to the selected agents and manages the team during the process of pursuit. If the evader is within the kill radius of some pursuit team members, the task is done; otherwise, D* algorithm is applied by each pursuit member to correct its path once the evader moves to a new position. Distributive in nature, it allows a UAV fleet to perform complex tasks in 3D space in a coordinated way. Simulation results show that the pursuit UAVs can dynamically form a pursuit team to catch evaders efficiently. It can be easily extended to cases of multiple pursuers versus multiple evaders.